The present invention relates to the field of providing protection against lightning for use in high temperature environments. A particular but non-exclusive field for the present invention is that of providing protection against lightning for hot parts present in the thrusters of launchers for space, or tactical, etc. purposes, or in aeroengines.
The thrusters to be found in such launchers or the after-body parts of aeroengines can be struck by lightning while they are in flight. When the part(s) struck by lightning is/are made of a non-conductive material, such as a composite material, or when they are covered in a dielectric material, their structure can be severely damaged by the pulse and the continuous components of the electric arc created by the lightning.
Various techniques already exist for providing protection against lightning, and they set out mainly to facilitate the flow of the electricity of the lightning through the protection rather than through the structure that is to be protected, thereby quickly increasing the size of the root or “termination” of the lightning arc so as to reduce its thermal and mechanical stresses.
Among presently-existing solutions, there are to be found coatings for providing protection against lightning that are constituted by:
metal fabrics fastened to the surface of the part that is to be protected;
metal grids that are deployed from a metal sheet having slots and that is stretched in order to form a grid, the grid likewise being fastened to the surface of the part that is to be protected;
conductive layers made by depositing particles of metal, e.g. particles of nickel, on the surface of the part that is to be protected in order to increase its conductivity; and
metal fibers woven directly in the fiber texture of the reinforcement of the composite material part that is to be protected in order to form a multitude of small points at the surface of the part that are suitable for dispersing the root of the lightning arc.
Nevertheless, those various coatings present certain drawbacks, of which the main drawback is that they withstand high temperatures poorly. In addition, some of those coatings are difficult to put into place on structures that are complex in shape.